Chemical synthesis of organic compounds is often a complex process that requires toxic catalysts, long reaction times, and many reagents. One example is the conventional synthesis of 2,1-benzisoxazole (BNZ). This compound has great importance for both pharmaceutical applications and as a starting material in the total synthesis of natural products.¹ Chemical synthesis of this compound requires use of ruthenium and palladium catalysts, high pressure of carbon monoxide, and long reaction times.² Also, the yield for the conventional chemical reaction is low, and there are no reports of yields higher than 50%.³

On the other hand, electrochemistry offers a clean and fast method for the synthesis of organic compounds. However, the electrosynthesis of BNZ has previously involved the use of a mercury pool cathode over a long reaction time, which makes the synthesis unfavorable.⁴ In the present work, the electrochemical behavior of o-nitrobenzaldehyde was studied in different solvent systems with the aid of cyclic voltammetry. Subsequently, the electrosynthesis of BNZ was accomplished with bulk electrolysis at a carbon cathode. Upon optimization, the yield of the BNZ reached 80% within a 1-hour electrolysis without any catalyst to facilitate the process.

References

1. Wiȩcław, M.; Bobin, M.; Kwast, A.; Bujok, R.; Wróbel, Z.; Wojciechowski, K. Mol. Divers. 2015, 19, 807–816.
2. Akazome, M.; Kondo, T.; Watanabe, Y. J. Org. Chem. 1994, 59, 3375–3380.
3. Genung, N. E.; Wei, L.; Aspnes, G. E. R. Org. Lett. 2014, 16, 3114–3117.
4. Fijalek, Z.; Zuman, P. Electroanal. 1993, 5, 53–64.